Diode harvests infrared energy to generate electricity

The team from KAUST (King Abdullah University of Science and Technology) has developed a proof-of-concept device that utilises infrared radiation, plus waste heat from industrial processes, by transforming quadrillionth-of-a-second wave signals into useful electricity.

Infrared heat can be harvested 24 hours a day and one way to achieve this is to treat waste or infrared heat as high-frequency electromagnetic waves. Using appropriately designed antennas, collected waves are sent to a rectifier, often a semiconductor diode, that converts alternating signals into an electric current.

According to KAUST, putting these 'rectenna' designs into practice has been difficult because infrared emissions have very small wavelengths and require micro or nanoscale antennas that are difficult to fabricate and test. Additionally, infrared waves oscillate thousands of times faster than a typical semiconductor can move electrons through its junction.

"There is no commercial diode in the world that can operate at such high frequency," said project leader Atif Shamim. "That's why we turned to quantum tunnelling."